B-rep

B-rep, or "Boundary Representation", is a way of describing the shape and structure of an object in a computer program. It's a bit like drawing a picture of the object, but instead of drawing lines and colors, the computer uses mathematical formulas to create a digital model of the object.

Imagine you have a toy car, and you want to make a digital copy of it on a computer. Using b-rep, you would start by drawing the car's shape, including the curves of the body, the wheels, the doors, and any other details. You would also need to include information about how the different parts of the car fit together - for example, how the wheels attach to the body, or how the doors open and close.

But the computer doesn't just draw a flat picture of the car - it also creates a 3D model that can be viewed and manipulated from different angles. This is important if you want to use the digital model to design modifications to the car, or to create animations or simulations of the car in action.

In summary, b-rep is a tool for creating digital models of objects that captures both their shape and structure, and allows for detailed manipulations and simulations in a computer program.